that would be the DOT target command
as in
.target 350
creating a target 350 yards from you to the direect north.
it would always be 350 yards from you (whatever distance you type) to the DUE north.
to remove it type (as in a DOT command i assume you are aware of)
.target 0
making the distance 0, thus voiding the "target" in witch to "practice" on.
hope that helps